You use blithe to indicate that something is done casually, without serious or careful thought.
例句
It does so with blithe disregard for best scientific practice.沒有考慮最科學的做法就輕率地這么做了。
ADJ-GRADED
無憂無慮的；快樂無憂的
Someone who is blithe is cheerful and has no serious problems.
例句
She said 'hi' with the blithe assurance of someone who knew how much she'd been missed.她高興地說了聲“嗨”，好像確信大家非常想念她似的。
英漢詞典釋義
adv.
歡樂地;快活地;無掛慮地
They blithely carried on chatting, ignoring the customers who were waiting to be served.他們繼續開心地聊天,將等著購物的顧客們置于一邊。He blithely ignored her protests and went on talking as if all were agreed between them.對她的抗議他毫不在意地拋諸腦后，只管繼續往下說，仿彿他們之間什么都談妥了似的。